In the past many types of sinkers and weights have been used to carry the fishing lure down to the bottom of a body of water with the goal of hooking the larger species of fish which are primarily bottom feeders.
Inventors have tried every means to create an apparatus to bring the lure down without startling the fish.
When a weight is tied to a line it must move with the line; therefore, when a fish strikes at the lure it will pull not only on the bait but also on the weight causing a resistance and frightening the fish away. Weights attached to a long thin wire as well as weights tied directly to a fishing line tend to stir up the bottom of the body of water and can easily become lodged in obstructions.
One of the obstacles people must overcome when using these weights is the cutting of the fishing line and retying the knot each time they require a new weight. Individuals with failing eyesight or arthritic conditions in the hands have found this to be cumbersome and in some cases impossible to do without the help of another individual.